Furnace for decorating ceramic ware



Sept. 25, 1923. 1,468,947

J. A. JEFFERY FURNAGE F-OR DECORATING CERAMIC WARE Filed April 18; 1921 a 4' y H Patented Sept. 25, E923.

JOSEPH A. JEFFERY, OF DETROIT, MICHIGAN, .ASSIGNOR TO THE JEFFERY-DEWITT COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MAINE.

FURNACE FOR DECORATING CERAMIC WARE.

Application filed April 18, 1921.

To all whom it may concern:

Be it known that I, JOSEPH A. JEFFERY, a citizen of the United States, and a resident of Detroit, in the county of Wayne and State of Michigan, have made an.

Invention Appertaining to Furnace for Decorating Ceramic Ware; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings,-and to the characters of reference marked thereon, which form a part of this specification.

My invention has for its object to provide a furnace or kiln for progressively heating and cooling ceramic ware, and at the same time causing a movement of one or more chemically active gases or vapors over the ware at a slow rate, producing maximum thermal economy and chemical efficiency.

It particularly has for its object to provide a means whereby ceramic ware may be rapidly and effectively decorated, and to this end it provides a means for gradually increasing the temperature of ceramic ware,

and for gradually cooling the ceramic ware while being subject to a slow current of air that will cause or permit certain modifications to take place in theware at the surface of the ware, whereby the decorative materials are chemically combined in an oxidizing atmosphere that will prevent the deoxidization of those coloring matters containing oxygen. The principal chemical function of the moving current of air being to combine with and carry oil the hydrocarbon compounds that have been mixed with the decorative materials (such as printing oil) and oxidizing them instead of permitting them to become oxidized by chemically combining with the oxygen of the coloring matter.

The invention may be contained and performed in furnaces and kilns of different forms and for different purposes. To illustrate a practical application of the invention, and for the purposes of description thereof, I have selected a kiln as an example such as infusorial earth and the like.

Serial No. 462,159.

of structures containing the invention, and shall describe it hereinafter. The illustrative kiln or furnace is shown in the accompanying drawings.

tric element 2 which is surrounded by heat insulating and current insulating material 3, The electric element may be formed of resistance wire, andmoreover may be made in the form of a coil. This, however, forms no part of my invention, and is selected merely as illustrative of the electric heating means for heating the furnace. The coil 2 is connected by lines 4 to a source of current supply. a

A tube 5 is located in proximity to the heat element 2. In the construction shown the tube 5 extends through the coil 2, and the coil 2 surrounds .only the central portion of the tube 5. The tube 5 is considerably longer than the shell 1, and thus may be considered to be divided into the three chambers 6, 7 and 8.

The shell 1 and the'tube 5 are supported at a slight angle to the horizontal, preferably about ten degrees by means of the legs or standards 9, which will cause the air to move slowly and at a substantially uniform rate through the tube, by convection 'produced by heating the central chamber 7 about which the coil 2-is located.

The articles are surfaced or coated or marked, or otherwise treated and are inserted in the upper end 11 of the tube 5, and the articles previously inserted in the tube are pushed along the tube the length of the articles. The size of the tube?) is slightly larger than the cross sectional area of the articles so as to confine the air current about the articles, and yet the tube is sufficiently large to permit flow of the air current.

The articles, such as the spark plug porcelains 12, will thus be successively raised in temperature while they are being moved through the chamber 8 until they reach a point near the chamber 7 and will be mainmoved through the chamber 7 and will be gradually lowered in temperature while bemg moved through the chamber 6. During the progressive movement-s, particularly when the temperature of the porcelains is rclatively higb thedecorative material isbeingaeted upon by the oxygen of the air which operates to form and ii): permanently the colors producible by the decorative materials, and moreover, reacts during the temperature range of-the particular reaction "b'etween the oxygen and the oxidizable ingredients of the decorative material to form and ii the colors of the decorative material within the glaze at its surface. Moreover the moving current carries away the hydrocarbon and "oxidizing them to prevent them from affecting the heated glaze of the porcelains within the tube. By this arrangement the oxygen of the moving air is ibrought into contact with the ceramic bodies, and also the heat is conveyed from the heated chamber to the ceramic bodies, and also to and from ceramicbodies without material loss of thermal etiicien'cy. The movement of the air through thc'tubular members therefore does not cause a material loss of the heat produced by the heating element, but operates in a slight degree to move the zone of high temperature toward the receiving end of the tube. The air entering the lower end 13 of the tube gradually cools the porcelains as they are carried from the zone oi high temperature. it is raised in iemperature'as it approaches the chamber 7 by the heat of the moving porcelains 12, until it has a temperature substantially that of the chamber 7. The air moreover-in its passage through the tube conveys its heat to the ceramic bodies as they approach the chamber 7, while it is being cooled by this transfer until it passes'out of the end ll of the tube 5.

As the porcelains are pushed progressively and step by step through the tube 5, they are delivered through the end 13 ofthe tube at a temperature somewhat above atmospheric temperature. They may be caught as they fall from the end of the tube 13 by-any suit able means if desired.

In order to forma smooth interior surface on which the porcelains may readilyride, and also in order that the tube may be protected from oxidization, the interior surface of the tube 5 may be coated or covered with a refractory material, or the tube itself may be made of a refractory material, such as porcelain, that will not fuse at the temperaturc to which the ceramic bodies are raised in the furnace. Preferably to allow or the expansion and contrat 'on due to temperature changes the tube 5 is lined with a plurality oi bushings 1%, formed of highly refractory material. that are placed end to end and may be formed of slightly beveled ends 15 to prevent the ceramic bodies or porcelains assen 12 from being caught by the corners of the bushings.

I claim:

1. In a furnace for progressively heating and chemically treating bodies. a tubular member having openings at its ends and in which bodies having oxidizable materials may be placed contiguously through one opening and moved by the insertion of the bodies-successively into the tubular member, means for directly heating only the central portion of the wall of the tubular member, the tubular member located at an angle to the horizontal and causing the movement of air into the opening at oneend through the tubular member and out through the opening at the other end and through which the bodies are inserted, the cross sectional area of the bodies and of the tubular member being so proportioned asto. control the movement ofthe air as to heat the air in advance of its-entry tothe central portion of the wall of the tubular member to permit'the heated oxygen to react on the surface materials of the bodiesv as they passthrough the central chamber of the tubular member and to permit the removal-"of" ases or vapors produced inthe central chain or.

2. In a furnace for-progressively heating and chemicallytreating bodies, a tubular -member having openings at its ends and in which bodies having oxidizable materials may be placed contiguously through one opening and moved by the insertion of the bodies successively into the tubular member,

means for directly heating only the central.

portion of the wall of the tubular member, the tubular member located at such an angle to the horizontal and causing the movement of air into the opening at one end through the tubular member and out through the opening at the other end and through which the bodies are inserted, and the cross sectional area of the bodies and of the tubular member being so proportioned as to control the movement of the air as to heat the air in advance of its entry to the central portion of the wall of the tubular member to permit the heated oxygen to react on the surface materials of the bodies as they pass through the central chamber of the tubular member and to permit the removal of gases or vapors roduced in the central chamber.

3. n a furnace r'or progressively heating bodies, a metallic tubular member in which the bodies are placed, a means for heating the tubular member, aporcelaineous lining located in the tubular member for protecting the bodies and the walls of the tubular member 4:. In a furnace for heating bodies a tubular member in which the bodies may be placed oontiguously and moved by the insertion of the bodies-successively into the ends of the tubular member, and having a plurality of bushings forming an interior lining to the tubular member, means for heating the central portion of the wall of 5 the tubular member, the tubular member located at an angle to the horizontal for causing the movement of the gaseous ma- JOSEPH A. JEFFERY,

terial through the tubular member. and thus forming cooling, temperature maintaining, and temperathre raising chambers. 10

In testimony whereof I have hereunto signed my name to this specification. 

